What does perf interupt mean?

This should not be a concern.perf is a tool to handle CPU performance. The kernal is capable of automatically determining the sample rate without affecting the performance of system. Here is a thread on this from the Arch forum.

This answer from the Arch Forum sums it up:

This message is informational and nothing to worry about.

It has to do with the Linux perf tool which is included in the kernel. The kernel automagically determines the sample rate that could be used without impacting system performance too much; and it logs this even when perf isn't active, or even installed.

Messages like this are triggered by high(er) system load or a cpu that is scaling.